Signalling equipment



Oct. 9, 1956 E. A. BRASS SIGNALLING EQUIPMENT Filed Jan. 22, 1953 m T N E V m AT'TUKNEY generator provided by the present invention can be varied so easily and quickly that authorized personnel can actually vary those signals during the course of a fire. Moreover, once the signals are changed, that signal generator can be set to repeat those signals any desired number of times. These features are extremely desirable since they enable authorized personnel to set up any desired signals in a short time, and then permit such personnel to devote their time to quelling the fire; the signal generator automatically transmitting the signal the desired number of times.

Many prior signal generators could not be halted after they had been started; and this is objectionable since it might be desirable to change the signal being generated and transmitted. The present invention obviates this objection by providing a signal generator which can be stopped at any time, and which can then have its signal changed before it is restarted. Such a signal generator avoids the sending of signals that are belatedly discovered to be erroneous, and it permits changing conditions at a fire to be reflected in changing signals from the signal generator.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description a preferred embodiment of the present invention is shown and described but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

The drawing is a schematic diagram of an alarm circuit that embodies the principles and teachings of the present invention.

In the drawing, the numeral denotes one contact of a normally open switch; and that contact is permanently connected to a source of power, which is indicated by the customary symbol for positive voltage. The other contact of that switch is denoted by the numeral 12, and the contacts 10 and 12 can be selectively connected together by the armature 14 of the switch. However, the armature 14 is normally held out of engagement with the contacts 10 and 12 by a spring, not shown.

A wiper switch has an armature 16 connected to contact 10, and it has a semi-circular contact 18. That switch also has a number of individual, circumferentiallyspaced contacts 20; and it has a number of interconnected, circumferentially-spaced contacts 22. The armature 16 of the wiper switch can engage the semi-circular contact 18 while simultaneously engaging one of the contacts 20 or one of the contacts 22. A multi-contact switch has a number of individual, circumferentially-spaced contacts 26 that are respectively connected to the individual, circumferentially-spaced contacts 20 of the wiper switch; and that multi-contact switch has a number of interconnected, circumferentially-spaced contacts 28 that are connected to the interconnected, circumferentially-spaced contacts 22 of the wiper switch. An armature 24 selectively engages the contacts 26 and 28 of the multi-contact switch.

The armature 24 is mounted on one end of a rotatable shaft 30, and the other end of that shaft carrier a ratchet 32. The ratchet 32 is shown as having only a limited number of teeth at its periphery, but that ratchet will have teeth over its entire periphery. A detent 34 is mounted adjacent the ratchet 32 and that detent will engage the teeth of the ratchet and limit rotation of the ratchet to one direction as long as that detent can engage the teeth of the ratchet 32. The detent 34 is resilient and is biased into engagement with the teeth of the ratchet 32. A combination pawl and relay armature 36 is pivoted adjacent the ratchet 32, and the upper end of that combination pawl and armature selectively engages the teeth of the ratchet 32. The armature of the combination pawl and armature is selectively attracted by an electromagnet 38. Whenever the armature of the combination pawl and armature is attracted by the elec tromagnet 38, the combination pawl and armature rotates in a clockwise direction and causes the pawl thereof to engage the teeth of the ratchet 32 and thus rotate the ratchet 32 in a clockwise direction. The spacing between the teeth on the ratchet 32 is such that movement of the ratched through the peripheral distance of one tooth will cause the armature 24 to move the distance between the spaced contacts 26 or 28 of the multi-contact switch. With this arrangement, energization of the electromagnet 38 will cause the ratchet 32 to step around its axis on the shaft 30 and move the armature 24 into engagement with the various contacts 26 and 28 of the multi-contact switch. A release lever 46 is pivoted adjacent the combination pawl and armature 36 and adjacent the detent 34. This lever has an armature at one end thereof which can respond to energization of the electromagnet 42. When the lever 40 is moved by the elcctromagnet 42, the upper end of that lever will urge the detent 34 out of engagement with the teeth of the ratchet 32 and will also urge the pawl of the combination pawl and armature out of engagement with the teeth of the ratchet 32. When this occurs, a spring, not shown, will rotate the ratchet 32 back to the position shown in the drawing. At such time, the armature 24 will be out of engagement with the contacts 26 and 28 of the multicontact switch.

The numeral 44 denotes a normally-open switch, and that switch is the start switch of the signal generator provided by the present invention. One terminal of that switch is connected to the semi-circular contact 18 of the wiper switch. The other terminal of the switch 44 is connected to a junction 46 adjacent a relay 48. One lead of the relay 48 is connected to the junction 46 and the other lead of that relay extends through junction 60 to the negative source of power indicated by the customary drawing symbol. The relay 48 has four contacts, 5t 52, 54 and 56 and those contacts are connected together for conjoint movement by a rod indicated by a dashed line in the drawing.

The numeral 64 denotes a relay which has two contacts 66 and 68. One of the leads of the relay 64 extends to a negative source of power, as indicated by the customary drawing symbol. The two contacts 66 and 68 of the relay 64 are connected together for conjoint movement by a rod indicated by dotted lines in the drawing. A signaling key 74 is located adjacent the contact 66 of the relay 64 and that key has one end thereof connected to a positive source of power, as indicated by the customary drawing symbol. An indicator 76, shown in the form of a lamp, is located adjacent the contact 63 of the relay 64. One end of this indicator is connected to ground. Although the indicator 76 is shown as being a lamp, it could be a gong, a recording instrument, or any of the customarily used indicators ruown in the fire alarm art.

A relay 78 has one of the leads thereof extending to a junction 86 which is connected to the armature 24 of the multi-contact switch. The other lead of relay extends to a negative source of power, as indicated by the symbol on the drawing. The relay 78 has t rec contacts, 80, 32 and 84; and those contacts are linked together for conjoint movement by a rod indicated by the dotted line on the drawing. The contact 30 of relay 78 is connected to contact 55) of relay contact 82 of relay 78 is connected to contact 52 of relay 48, and contact 84 of relay 78 is connected to the electro magnet 42. The three contacts 89. 82 and S4 of the relay 78 are connected together by junctions 88 and 90.

A relay 92 has one of its leads connected to the contact 12 of the normally open switch which has the armature 14. The other lead of the relay 92 is connected to a negative source of power as indicated by the symbol on the drawing. The relay 92 has four contacts, 94, 96, 98 and 100. These contacts are connected together for conjoint movement by a rod indicated by dotted lines on the drawing. The contact 94 is connected to the junction 86 adjacent the relay 78. The contacts 96 and 98 are connected together through junction 108, and contact 100 is connected through junction 110 to one lead of the relay 64.

A relay 112 has one lead thereof connected to the junction 72 adjacent the contact 66 of relay 64 and adjacent the signalling key 74. The other lead of the relay 112 is connected to a negative source of power as indicated by the symbol on the drawing. The relay 112 has a contact 114 which selectively opens and closes a circuit which includes an indicator 116 and a battery 118. While the indicator 116 is shown as being a gong, that indicator could be a light, a recording instrument, or any of the other signal detectors used in the fire alarm art.

The numeral 120 denotes a relay which has one lead thereof connected through a contact 128, through a junction 123 to the contact 56 of the relay 48. The other lead of the relay 120 is connected to a negative source of power as indicated by the symbol on the drawing. The relay 120 has a contact 122.

A group of slow-acting relays 124, 130, 134 and 138 is provided which constitute a pulse generator. These relays have contacts which move whenever the relays are energized; and while the relays are known as slow-acting relays, the contacts thereof move into and out of position in fractions of a second. Relay 124 has two contacts 126 and 128, relay 1311 has a contact 132, relay 134 has a contact 136 and relay 138 has a contact 140. A single pole double throw switch 142 is disposed between junction 144, contact 140 and junction 150; and a single pole double throw switch 143 is disposed between contact 126, junction 151i one lead of relay 134. The movable contacts of the switches 142 and 143 are connected together for conjoint movement by a rod indicated by dotted lines in the drawing. One lead of each of the relays is connected to a source of negative power, as indicated by the symbol on the drawing. The otherv lead of relay 124 is connected to contact 132 of relay 130, the other lead of relay 130 is connected to contact 136 of relay 134, the other lead of relay 134 is selectively connected by switch 143 to junction 150 or to contact 126 of relay 124, and the other lead of relay 138 is connected to: contact 126 of relay 124. The movable contacts of the single pole double throw switches 142 and 143 will normally be in engagement with either the upper contacts or the lower contacts of those switches rather than in the intermediate positions shown on the drawing.

When the movable contacts of switches 142 and 143 engage the upper contacts of those switches, and when junction 144 is connected to a source of positive power, current will flow through several paths; first, through junction 146, contact 136 and relay 130 to the source of negative power; second, through junction 146, junction 14%, contact 132 and relay 124 to the source of negative power; and third, through junction 146, junction 148, contact 126 switch 143 and relay 134 to the source of negative power. The current passing through relay 138 will energize that relay and raise the contact 132 thereof upwardly; thus breaking the circuit of relay 124. Meanwhile the current passing through relay 134 has been generating an ever-increasing pull on contact136; and when that pull is great enough, contact 136 will move upwardly and break the circuit to relay 13d. Thereupon, the contact 132 of relay 130 will move toward its closed position; and When it reaches that position, relay 124 will be energized. The energization of relay 124 will raise contacts 126 and 12 3; and the raising of contact 126 will open the circuit to relay 134. Thereafter the contact 136 of relay 134 will move to closed position and complete the cycle by causing energization of the relay 130. This cycle of successive raising of the con tacts 132, 136, and 126 and 128 will be repeated continuously as long as the movable contacts of switches 142 and 143 are in their upper positions, and junction 146 is connected to a source of positive power. The relays will be energized and deenergized at a steady uniform rate; and they will thus cause opening and closing of the contact 128 at a steady, uniform rate. This enables contact 128 to generate constant duration, equally spaced pulses in the circuit of which it is a part. When power is first applied to junction 144, relay 124 or relay 134, rather than relay 131), may be the first to become energized; but the matter of which relay is .the first to be energized is not critical. It is only necessary that the relays cyclically raise and lower the contact 128.

When the movable contacts of the switches 142 and 143 are in engagement with the lower contacts of those switches, and when the junction 144 is connected to a source of positive power, current will flow through four paths: first, through switch 142, through contact 140, through switch 143 and relay 134 to the source of negative power; second, through junction 146, contact 136 and relay 138 to the source of negative power; third, through junction 146, junction 148, contact 132 and relay 124 to the source of negative power; and fourth, through junction 146, junction 148, contact 126, and relay 138 to the source of negative power. The current passing through relay 134 will energize that relay and raise the contact 136 thereof upwardly; thus breaking the circuit of relay 13%;. Meanwhile the current passing through relay 138 has been generating an ever-increasing pull on contact 140; and when that pull is great enough, contact 140 will move upwardly and break the circuit to relay 134. Current has also been flowing through relay 124, and that current will act to raise the contacts 126 and 128 upwardly; the raising of contact 126 breaking the circuit to relay 138. When contact 148 was raised by relay 138, relay 134 permitted its contact 136 to close the circuit of relay 131); and that relay now raises its Contact 132 upwardly to break the circuit of relay 124. When contact 126 was raised by relay 124, relay 138 permitted its contact 140 to complete the cycle by closing the circuit to relay 134. This cycle of successive raising of the contacts 136, 140, 126 and 128, and 132 will be repeated continuously as long as the movable contacts of switches 14?. and 143' are in their lower positions, and junction 146 is connected to a source of positive power. ergized at a steady uniform rate; and they will thus cause opening and closing of the contact 128 at a steady and uniform rate. However, the rate at which relays 124, 135), 134 and 138 open and close the cont-act 128 will be slower than the rate at which the relays 124, and 134 can open and close that contact, because four relays, rather than just three, must energize and deenergize between each opening of contact 128. When power is first applied to junction 144, relay 124 or relays 134 or 133 or relay 138 may be the first to become energized; but the matter of which relay is the first to be energized is not critical. It is only necessary that the relays cyclically actuate the contact 123.

If desired, other pulse generating devices could be substituted for the relays 124, 131), 134 and 138. However, those relays have been found to be particularly desirable since they can operate only when the relay 124 opens and closes its contac 12.6 and 128; and therefore the relays cannot operate without also operating the contact 123. In this way, the circuit provided by the present invention positively avoids a situation where the pulse generator might work but would not supply the pulses to the circuit itself.

A junction 152 is connected to a source of positive power, as indicated by the symbol on the drawing, and that junction is also connected to junction 102 adjacent the contact 94 of relay 92. The junction 152 is also connected to a junction 154 which is adjacent the contact The relays will be energized and deen- 158 of relay 156. The contact 158 of the relay 156 is connected to the junction 104 adjacent the contact 96 of relay 92. One of the leads of the relay 156 extends to a source of negative power, as indicated by the symbol on the drawing. The other lead of relay 156 extends to junction 160; and junction 168 is connected to the contact 166 of a relay 162. One lead of the relay 162 is connected to a source of negative power, as indicated by the symbol on the drawing. The other lead of that relay is connected to a junction 168; and junction 168 is connected to the contact 122 of relay 120 and is also connected to the contact 164 of the relay 162. In addition to the contacts 164 and 166, the relay 162 has an armature 172, and the lower end of that armature is a pawl. The pawl selectively engages the teeth on a ratchet 173 mounted adjacent the armature 172. While the drawing only shows a limited number of teeth at the periphery of the ratchet 173, that ratchet will have teett extending continuously around its periphery. The ratchet 173 is mounted on a shaft 180. A detent 174 is mounted adjacent the ratchet 173 and the free end of that detent selectively engages the teeth of that ratchet. The detent will permit the ratchet to rotate in a clockwise direction but will prevent rotation of that shaft in a counterclockwise direction. A spring 1'78 holds the detent 174 in engagement with the teeth of the ratchet 173, and a spring 176 holds the pawl of armature 172 in engagement with the teeth of ratchet 173. The springs 176 and 178 are yieldable to permit the ratchet 173 to he stepped around in a clockwise direction by the pawl on armature 172 and to permit the detent 174 to slip past the teeth of the ratchet as it moves in that direction.

A shaft 182, which can be an extention of the shaft 180 or can be geared to be driven by that shaft, is provided with a number of multicontact switches. These switches consist of a number of circularly disposed contacts and rotatable armatures, and two such switches are connected together to provide one switch with three hundred and sixty degrees of rotation. If desired, switches could be provided which are equipped with contacts throughout an angular distance of three hundred and sixty degrees, but it is cheaper to provide two switches which each provide one hundred and eighty degrees of angular distance. Thus, the contacts 184 and 188 provide the equivalent of circular contacts disposed around three hundred and sixty degrees. There are twenty-six contacts 184 and there are twenty six contacts 188, making a total of fifty-two contacts for the first combined switch. An armature 186 is selectively engageable with each of the contacts 184, and an armature 190 is selectively engageable with each of the contacts 188. The armatures 186 and 190 are slightly more than one hundred and eighty degrees apart so that the armature 190 will be out of engagement with the contacts 188 until the armature 186 has moved out of engagement with the twenty-sixth contact 184. Thereupon, the armature 190 will engage the first contact 188 which is the twenty-seventh contact of the combined switch. Each of the first nine contacts 184 have conductors connected to them, the tenth contact 184 does not have a conductor connected to it, the eleventh through the nineteenth contacts 184 have conductors connected to them, the twentieth contact has no conductor connected to it, the twenty-first through the twenty-sixth contact 184 and the first through the third contacts 188, which are the twenty-seventh through the twenty-ninth contacts of the combination switch, have conductors connected to them. The fourth through the twenty-sixth contacts 188, which are the thirtieth through the fifty-second contact of the combination switch do not have any conductors connected to them. The conductors which are connected to the various contacts 184 and 188 are individually insulated from each other but they are combined together into a cable 266.

A second combination switch, similar to the combination switch formed of contacts 184 and 188 and armatures 186 and is disposed adjacent the shaft 182. That switch has circularly arranged contacts 192 and 196 and those contacts are comparable to the contacts 184 and 188. The armatures 194 and 198 are comparable to the armatures 186 and 190. The first nine contacts 192 have conductors connected to them. The tenth contact 192 has no conductor connected to it, the eleventh through the nineteenth contacts 192 have conductors connected to them, the twentieth contact 192 has no conductor connected to it, the twenty-first through the twenty-sixth contacts 192 have conductors connected to them, the first through the third contacts 196, which are the twentyseventh through the twenty-ninth contacts of the combination switch, have conductors connected to them, the fourth contact 196 which is the thirtieth contact of the combined switch has no conductor connected to it, the fifth through the thirteenth contact 196, which are the thirtieth to thirty-ninth of the combined switch, have conductors connected to them, the fourteenth contact 196 which is the fortieth contact of the combined switch has no conductor connected to it, the fifteenth through the twenty-third contact 196, which are the forty-first through the forty-ninth contacts of the combination switch have conductors connected to them, and the twenty-fourth through the twenty-sixth contact 196, which are the fiftieth through the fifty-second contacts of the combination switch have no conductors connected to them. The conductors which are connected to the contacts 192 and 196 are insulated from each other but are bound together in a cable 268. The armatures 186 and 199 are connected together by the junctions 256 and the armatures 194 and 198 are connected together by the junctions 258 and 260.

A third combination switch, comparable to the first two combination switches, is mounted adjacent the shaft 182. This switch has circularly disposed contacts 200 and 204 and has armatures 202 and 206. The first and second contacts 200 are connected together and to a conductor, but the rest of the contacts 200 are not connected to conductors or to each other. The fifty-first contact of the combination switch, which is the twenty-fifth con tact 204, is connected to a conductor. The armatures 202 and 206 are connected together by the junction 262.

A fourth combination switch, comparable to the first three combination switches, has circularly disposed contacts 210 and 214, and has armatures 212 and 216. The first contact 210 is not connected to a conductor. The tenth contact 210, the twentieth contact 210, the fourth contact 214, which is the thirtieth contact of the combination switch, the fourteenth contact 214, which is the fortieth contact of the combination switch, and the twentyfourth through the twenty-sixth contacts 214, which are the fiftieth through the fifty-second contacts of the combination switch, are all connected together by a conductor 290. The rest of the contacts 210 and 214 are connected together by a conductor 288.

The numeral 220 denotes the commutator of a commutator switch that has nine circularly disposed contacts 218. The commutator 220 can engage and selectively connect together one through nine of the contacts 218. The first through the ninth contacts 218 are respectively connected to the first through the ninth contacts 184 of the first combination switch. A junction 272 is provided on the commutator 220 and a jumper 270 extends from that junction to the first contact 218. The commutator 220 is mounted on one end of a shaft and a earn 222 is mounted on the other end of that shaft; the shaft being indicated by a dotted line in the drawing. The cam 222 normally holds a switch 224 closed, but the cam will rotate with the commutator 220 to permit the switch 224 to open. The commutator 220 can be rotated by hand but it will remain in any position in which it is set.

A plurality of circularly disposed contacts 226 have commutator 228 which can selectively cover one through nine of those contacts. The commutator 228 is moved by '9 hand and it will remain in any position in which it is set. The first through the ninth contacts 226 are respectively connected to the eleventh through the nineteenth contacts 184 of the first combination switch.

A group of nine circularly disposed contacts 230 are selectively connected together by the commutator 232 of a commutator switch. The commutator 232 can be moved by hand and it will remain in whatever position it is set. The first through the ninth contacts 23% are respectively connected to the twenty-first through the twenty-ninth contacts of the first combination switch which are the twenty-first through the twenty-sixth contacts 184 and the first through the third contacts 188. The commutators 226, 228 and 232 are connected together by the junctions 2'72 and 274.

A group of five commutator switches have a number of groups of nine circularly disposed contacts which are engageable by rotatable commutators, and those contacts are connected to the contacts of the second combination switch. Thus, the nine contacts 234 are connected to the first nine contacts 192 of that combination switch; the first through the ninth contacts 234 being connected respectively to the first through the ninth contacts 192. The contacts 234 are selectively connected together by the commutator 236. A junction 275 is provided on the commutator 236 and a jumper extends between that junction and the first contact 234. The first through the ninth contacts 238 of the second commutator switch of the group of five are connected respectively to the eleventh through the nineteenth contacts 192 of the combination switch. The contacts 238 are selectively connectable together by the commutator 240. The first through the ninth contacts 242 of the third commutator switch of the group of five are respectively connected to the twenty-first through the twenty-ninth contacts of the second combination switch, which are the twenty-first through the twenty-sixth contacts 192 and the first through the third contacts 196. The contacts 242 are selectively connectable together by the commutator 244. The first through the ninth contacts 246 of the fourth commutator switch of the group of five are respectively connected to the thirty-first through the thirty-ninth contacts of the second combination switch, which are the fifth through the thirteenth contacts 196. The contacts 246 are selectively connectable together by the commutator 243. The first through the ninth contacts 250 of the fifth commutator switch of the group of five are respectively connected to the forty-first through the forty-ninth contacts of the second combination switch which are the fifteenth through the twenty-third contacts 196. The contacts 250 are selectively connectable together by the commutator 252. The commutators 236, 240, 244, 248 and 252 are all connected together by the junctions 275, 278, 280, 282 and 284.

The armatures of the group of five commutator switches are connected to one terminal of relay 292. Another terminal th of the relay 292 is connected to the commutators of the group of three commutator switches. The two terminals 3% and 302 are spaced apart and cannot be connected together. The armature 298 of the relay 292 selectively engages the terminals 300 and 382 but cannot at any time connect those terminals together. The relay 292 has two other armatures 294 and 296; the armature 294 selectively engaging the terminal 295 and the armature 296 selectively engaging the terminal 297. The three armatures 294, 296 and 298 are connected together for conjoint movement by a rod, as indicated by dashed lines in the drawing. The terminal 304 is connected to the switch 224 and the armature 294 is also connected to the switch 224 through the junction 308; and thus the terminal 295 and the armature 294 are in parallel with the switch 224.

The group of three commutator switches coact with the first combination switch to generate the pre-code signal, while the group of five commutator switches and the sec- 0nd combination switch generate the code signal. The commutators 228, 228 and 232 are manually set to select the desired pre-code signal, and those commutators can be set to provide any pre-code signal from one through nine hundred and ninety nine. For the purposes of this description it will be assumed that the commutator 220 is set to connect together the first and second contacts 218, that the commutator 228 is set to connect together the first, second and third contacts 226, and that the commutator 232 is set to connect together the first through the fourth contacts 230. This will enable the group of three commutator switches and the first combination switch to generate and transmit a pre-signal code two, three, four. The group of five commutator switches can coact with the second combination switch to generate and transmit a code signal from one through ninety nine thousand nine hundred and ninety nine. For the purposes of this description it will be assumed that the commutator 236 connects together the first five contacts 2.34, that the commutator 240 connects together the first six contacts 238, that the commutator 244 connects together the first seven contacts 242, that the commutator 248 connects together the first eight contacts 246, and that the commutator 252 connects together .all nine contacts 250. This will enable the group of five commutator switches to coact with the second combination switch to generate and transmit a code signal five, six, seven, eight and nine.

The pre-code signal and the code signal must be preset before the signal generator is placed in operation, and this is easily done by rotating the commutators to the proper position. The contacts of the commutator switches will be appropriately numbered to enable the operator to set the commutators properly. In addition, the number of rounds desired must be set. This is accomplished by setting the armature 16 in engagement with the desired contacts 20 or 22. These contacts will be properly numbered to enable the operator to set the armature 16 correctly. For the purposes of this description, it will be assumed that the armature 16 is set on the bottom-most of the contacts 22.

The signal generator provided by the present invention will be in a fire alarm box and that box will have a handle which can be moved to close the switch 44. Current will immediately flow from the source of positive power adja- 1 cent the terminal 10, through armature 16, through semicircular contact 18, through switch 44, through junction 46, through relay 48 and through junction 60 to the source of negative power; thus energizing the relay 48. The various contacts 22 will be charged as will the various 1 contacts 28, but no current will flow to the contacts 28 because the armature 24 is out of engagement with those contacts. The energization of the relay 48 will close contacts 50, 52, 54 and 56; and the closing of contact 50 will establish a holding circuit from the source of positive power adjacent the junction 152, through the junction 153, through the junction 90, through the junction 88, through the contact of relay 78, through the contact 50, through the junction 46, through the relay 48 and through the junction 60 to the source of negative power. This holding circuit will remain effective until relay 78 is energized to break that circuit at the contact 80, as by raising the contact 80. With this arrangement even a momentary closure of the switch 44 will start the operation of the signal generator since the holding circuit will keep the relay 48 energized.

Closure of the contact 52 of the relay 48 will establish a circuit from the source of positive power adjacent the junction 152 through junction 152, through junction 153, through junction 90, through junction 88, through contact 82, through contact 52, through junction 58, through junction 144 and through the pulse-generating chain of relays 124, 130, 134 and 138 to the source of negative power indicated on the drawing. This causes that chain of relays to energize and deenergize successively and cause cyclical opening and closing of the contact 128. The opening and closing of the contact 128 successively opens and closes a circuit which extends from the source of positive power adjacent the junction 152, through junction 152, through junction 153, through junction 90, through junction 88, through contact 82, through contact 52, through junction 58, through junction 62, through contact 56 of relay 48, through junction 123, through contact 128 and through relay 120 to the source of negative power indicated by the symbol on the drawing. The opening and closing of this circuit successively opens and closes the contact 122 controlled by the relay 120.

The closing of contact 52 of relay 48 charges junction 58, junction 62, junction 262, armatures 202 and 206 of the third combination switch and terminal 297 of relay 292. However, current will not flow because the armature 296 is not in engagement with the terminal 297 when the signal generator starts; the relay 292 being deenergized.

The closing of contact 54 of relay 48 connects the source of negative power adjacent junction 60 with one lead of the relay 292 through the junction 60 and the contact 54. However current will not flow through the relay 292 since the armature 206 is out of engagement with the twenty-fifth contact 204, which is the fifty-first contact of the third combination switch; that armature being connected to a source of positive power through the junction 262, through the junction 62, through the junction 58, through the contact 52, through the contact 82, through the junctions 88 and 90, and through the junctions 153 and 152.

The closing of contact 56 of relay 48 will complete a circuit which extends from the source of positive power adjacent junction 152, through junctions 152 and 153, through junctions 90 and 88, through contacts 82 and 52, through junctions 58 and 62, through contact 56, through junction 123, through contact 122, through junction 168, and through relay 162 to the source of negative power indicated on the drawing. This will energize the relay 162, thus causing opening of the contacts 164 and 166 and causing movement of the armature 172 in a clockwise direction to enable the pawl thereof to slip over one tooth and engage the next tooth. This last circuit will open and close cyclicly because of the pulses generated by the chain of relays 124, 130, 134 and 138 which cyclicly open and close the contact 128; which ccfntact in turn cyclicly opens and closes the relay 120, which cyclicly opens and closes the contact 122. As a result, the relay 162 is energized and de-energized. The opening and closing of the contact 166 will complete a circuit which extends from the source of positive power adjacent the junction 152, through the junction 152, through the junction 154, through the junction 254, through the junction 256, through the armature 186, through the first contact 184, through the first contact 218 and in parallel through the jumper 270 and through the commutator 22:: to the junction 272, through the terminal 399, through the armature 298 of relay 292, through the junction 1.60 adjacent relay 156 and through contact 166, through junction 110 and through relay 64 to the source of negative power indicated on the drawing. This circuit will respond to cyclical opening and closing of the contact 166 to cyclicly energize the relay 64, which in turn will cyclicly open and close the contacts 66 and 68. The closing of the contacts 66 and 68 will energize the indicolor 76 and the relay 112; a by the flow of current from the source of positive voltage adjacent the junction 7 through the contact 68 and the indicator 76 to ground in the one instance and through the junction 70, through the contact 66, through the junction 72 and through the relay 112 to the source of negative power indicated on the drawing. The relay 112 will selectively open and close the contact 114 which will selectively energize and decnergize the indicator 116 by means of the battery 11%. The indicator 76 can be located at the signal generator or can be located at the central station. The indicator 116 will be located at the central station, and the battery 118 can also be located at the central station. With this arrangement, each time the relay 162 is energized and tleenergized, an indication of that occurrence will be transmitted to the central station. Each time the relay 162 is energized by the closing of the contact 122, the armature 172 will be pulled over to cause the pawl thereon to move out of engagement with one tooth and into engagement with the next succeeding tooth. The subsequent deenergization of the relay 162 will ena le th spring 176 to pull the armature 172 to the position shown in the drawing and thus cause the ratchet 173 and the shaft to rotate the distance of one of the teeth on the ratchet 173. This will cause the armatures 186, 190, 19 195-3, 202, 206, 21.2, and 216 to move the distance between adjacent contacts of the combination switches. Thus, there will be a step by step advancement of each of the armatures of the combination switches due to the opening and closing of the contact 122 in response to the pulses generated by the relay chain 124, 130, 134 a d 133.

A slow-acting relay 156 has one lead thereof connected to a source of negative power, as indicated on the drawing, and it has its other lead connected to a source of positive power through junction 160, through armature 292 of relay 292, through terminal 300 of relay 292, through one or the other of the commutator switches in the group of three commutator switches, through the first combination switch, and through junctions 254, 154, and 152. The circuit of relay 156 will be broken during the moments the armatures 186 and of the first combination switch are moving out of engagement with one contact and into engagement with the next contact, but the slow-acting nature of that relay will keep it from becoming de-energized during those short intervals. As a result, the relay 156 will remain energized until the armature 186 moves out of engagement with that contact 184 which corresponds to the highest-numbered contact 2.18 engaged by the commutator 220. At such time the circuit from junction 152, through junctions 154 and 254, through the first combination switch and one or the other of the group of three commutator switches, through terminal 300, and through armature 293 to relay 156 will be broken, and that relay will become tie-energized; whereupon contact 158 will close.

The closing of contact 158 will establish a circuit from the source of positive power adjacent junction 152, through junction 152, through junction 154, through contact 158, through junction 104, through conductor 238, through that contact which is engaged by armature 212, through junction 264, through contact 164 and through relay 162 to the source of negative power indicated on the drawing. This circuit will energize relay 162 and simultaneously attract armature 172 and open the contact 164; the opening of contact 164 immediately de-energizing relay 162 and permitting spring 176 to cause armature 172 to advance the ratchet 173 the distance of one tooth. The relationship of the relay 162 and the contact 164 is that of the coil and contact of a buzzer; and as a result the relay will be energized and de-energized at a very rapid rate, and will advance the ratchet 173 and shafts 180 and 182 at a very rapid rate. This very rapid advancement will continue until the armature 212 moves out of engagement with the ninth contact 219 and into engagement with the tenth contact 210; that tenth contact not being connected to conductor 288, and the conductor 290 to which it is connected extending to the normallyopen contacts 96 and 98 of relay 92. The buzzer action of relay 162 will be far more rapid than the pulsing action of that relay due to pulses from the relay chain 124, 130, 134 and 138. With this arrangement the pulses from the relay chain 124, 130, 134 and 138 will act through relay 120 to energize and tie-energize relay 162 at a rapid rate, thus advancing the shaft 182 by steps and concomitantly acting through contact 166 and relays 64 and 112 to generate impulses for indicator 116. When the shaft 182 carries the armature 186 beyond the contact 184 corresponding to the highest-numbered contact 218 engaged by the commutator 220, the circuit to the relay 64 is broken at the next higher contact 218, thus preventing the sending of more impulses to indicator 116, and relay 156 is de-energized, thus permitting the buzzer action to quickly advance armature 212 to the tenth contact 210. The circuits to relay 156 and to relay 64 will be restored when the next pulse from the relay chain advances the armature 136 into engagement with the eleventh contact 184; and impulses corresponding to the setting of commutator 228 will be transmitted to indicator 116. After the pulses have advanced armature 1S6 beyond the contact 184 which corresponds to the highest-numbered contact 226 engaged by commutator 228, the circuits to relays 156 and 64 will be broken; and no further impulses will be transmitted to indicator 116, and the buzzer action will advance armature 186 to the twentieth contact 184. The circuits to relays 156 and 64 will again be restored when the next pulse from the relay chain advances the armature 186 to the twenty-first contact 184; and impulses corre sponding to the setting of commutator 232 will be transmitted to indicator 116. After the pulses have advanced armature 186 beyond that contact of the first combination switch which corresponds to the highest-numbered contact 230 engaged by commutator 232, the circuits to relays 156 and 64 will be broken; and no further impulses will be transmitted to indicator 116, and the buzzer action will advance armature 190 to the thirtieth contact of the first combination switch, which is the fourth contact 188. The buzzer action minimizes busy time between the numerals of the signal.

With the particular pre-code signal selected for the purposes of this description, the first pulse from the relay chain Will move the pawl on armature 172 into engagement with the next tooth on ratchet 173 and will open contact 166, thus de-energizing relay 64 with consequent generation of an impulse for indicator 116 by the opening of contact 114 by relay 112. As the first pulse passes, the spring 176 will advance armature 186 out of engagement with the first contact 184 and into engagement with the second contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The second pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again de-energizing relay 64 with consequent generation of a second impulse for indicator 116 by the opening of contact 114 by relay 112. As the second pulse passes, the spring 176 will advance armature 186 out of engagement with the second contact 184 and into engagement with the third contact 184; and this will immediately break the circuit to relay 64 since the commutator 220 does not engage the third contact 218 that corresponds to the contact 184 engaged by armature 186. As a result, relay 64 will continue to remain de-energized and relay 112 will hold contact 114 against further movement and against further generation of impulses. The third pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth on ratchet 173, and will again open contact 166. However since the circuit to relay 64 is already open, this movement of contact 166 will not aifect that relay or contact 114; and hence no further impulse is transmitted to indicator 116. As the third pulse passes, the slow-acting relay 156 will release its contact 158 because the circuit to that rel-ay was broken when the armature 186 moved out of engagement with the second contact 184; and that break in the circuit kept that relay from receiving the third pulse, which it needed to continue to remain energized. Before the fourth pulse can be generated, contact 164, relay 162, armature 212, and the third through the ninth contacts 210 will have started the buzzer action and 14 thus stepped armature 212 around to the tenth contact 210 and armature 186 around to the tenth contact 184.

The fourth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth of ratchet 173 and will open contact 166; but this movement of that contact will not affect relay 64 since the circuit is broken at the tenth contact 184. It will be noted that no impulses were sent to indicator 116 during the third and fourth pulses from the relay chain; and the absence of such impulses constitutes a blow that fully distinguishes the first numeral of the pre-code signal from the other numerals of that signal. As the fourth pulse passes, the spring 176 will advance armature 186 out of engagement with the tenth contact 184 and into engagement with the eleventh contact 184, and will permit contact 166 to close. Immediately, current will flow from the source of positive power adjacent junction 152, through junctions 152 and 154, through junctions 254 and 256, through armature 186, through the eleventh contact 184, through the first contact 226, through commutator 228, through junctions 274 and 272, through terminal 300, and through armature 298 to junction 160; and part of that current will energize relay 156 and the rest will flow through contact 166 and through junction to relay 64. The energization of relay 156 will open contact 158 and halt further buzzer action, and the energization of relay 64 will de-energize relay 112 and permit contact 114 to close. The fifth pulse will move the pawl on armature 172 into engagement with the next tooth on ratchet 173 and will open contact 166, thus de-energizing relay 64 with consequent generation of an impulse for indicator 116 by the opening of contact 114 by relay 112. As the fifth pulse passes, the spring 176 will advance armature 186 out of engagement with the eleventh contact 184 and into engagement with the twelfth contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The sixth pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again de-encrgizing relay 64 with consequent generation of a second impulse for indicator 116 by the opening of contact 114 by relay 112. As the sixth pulse passes, the spring 176 will advance armature 186 out of engagement with the twelfth contact 184 and into engagement with the thirteenth contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The seventh pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again de-energizin-g relay 64 with consequent generation of a third impulse for indicator 116 by the opening of contact 114 by relay 112. As the seventh impulse passes, the spring 176 will advance armature 186 out of engage ment with the thirteenth contact 184 and int-o engagement with the fourteenth contact 184; and this will inn mediately break the circuit to relay 64 since the commutator 228 is out of engagement with the fourth contact 226 that corresponds to the contact 184 engaged by armature 186. As a result, relay 64 will continue to remain de-energized and relay 112 will hold contact 114 against further movement and against further generation of impulses. The eighth pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth on ratchet 173, and will again open contact 166. However, since the circuit to relay 64 is already open, this movement of contact 166 will not affect that relay or contact 114; and hence no further impulse is transmitted to indicator 116. As the eighth pulse passes, the slow-acting relay 156 will release its contact 158 because the circuit to that relay was broken when armature 186 moved out of engagement with the thirteenth contact 184; and that break in the circuit kept that relay from receiving the eighth pulse, which it needed to continue to remain energized. Before the ninth pulse can be generated, contact 164, relay 162, armature 212, and

the fourteenth through the nineteenth contacts 210 will have started the buzzer action and thus stepped armature 212 around to the twentieth contact 210 and stepped armature 186 around to the twentieth contact 184. The absence of an impulse to the indicator 116 during the eighth pulse from the relay chain constitutes a blow, and it differentiates the second numeral of the pre-code signal from the first numeral of that signal.

The ninth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth of ratchet 173 and will open contact 166; but this movement of that contact will not affect relay 64 since the circuit is broken at the twentieth contact 184. As the ninth pulse passes, the spring 176 will advance armature 186 out of engagement with the twentieth contact 184 and into engagement with the twenty-first contact 184, and will permit contact 166 to close. Immediately, current will fiow from the source of positive power adjacent junction 152, through junctions 152 and 154, through junctions 254 and 256, through armature 186, through the twenty-first contact 184, through the first contact 230, through commutator 232, through junctions 274 and 272, through terminal 300, through armature 298 to junction 160; and part of that current will energize relay 156 and the rest will flow through contact 166 and through junction 110 to relay 64. The energization of relay 156 will open contact 158 and halt further buzzer action and the energization of relay 64 will de-energize relay 112 and permit contact 114 to close. The tenth pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth on ratchet 173 and will open contact 166, thus de-energizing relay 64 with consequent generation of an impulse for indicator 116 by the opening of contact 114 by relay 112. As the tenth pulse passes, the spring 176 will advance armature 186 out of engagement with the twenty-first contact 184 and into engagement with the twenty-second contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The eleventh pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again de-energizing relay 64 with consequent generation of a second impulse for indicator 116 by the opening of contact 114 by relay 112. As the eleventh pulse passes, the spring 176 will advance armature 186 out of engagement with the twenty-second contact 184 and into engagement with the twenty-third contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The twelfth pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again de-energizing relay 64 with consequent generation of a third impulse for indicator 116 by the opening of contact 114 by relay 112. As the twelfth pulse passes, the spring 176 will advance armature 186 out of engagement with the twenty-third contact 184 and into engagement with the twenty-fourth contact 184; and contact 166 will close, permitting relay 112 to close contact 114. The thirteenth pulse from the relay chain will move the pawl on armature 172 into engagement with the next tooth of ratchet 173 and will again open contact 166, thus again tie-energizing relay 64 with consequent generation of a fourth impulse for in dicator 116 by the opening of contact 114 by relay 112. As the thirteenth pulse passes, the spring 176 will advance armature 186 out of engagement with the twenty-fourth contact 184 and into engagement with the twenty-fifth contact 184; and this will immediately break the circuit to relay 64 since the commutator 232 is out of engagement with the fifth contact 230 that corresponds to the contact 184 engaged by armature 186. As a result, relay 64 will continue to remain de-energized and relay 112 will hold contact 114 against further generation of impulses. The fourteenth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth on ratchet 173, and will again open contact 166. However, since the circuit to relay 64 is already open, this movement of contact 166 will not affect that relay or contact 114; and hence no further impulse is transmitted to indicator 116. As the fourteenth pulse passes, the spring 176 will move armature 212 into engagement with the twenty-sixth contact 210, and the slowacting relay 156 will release its contact 158 because the circuit to that relay was broken when the armature 186 moved out of engagement with the twenty-fourth contact 184; and that break in the circuit kept that relay from receiving the fourteenth pulse, which it needed to remain energized. Before the fifteenth pulse can be generated, contact 164, relay 162, armatures 212 and 216, and the twenty-sixth contact 210 and the first three contacts 214 will have started the buzzer action and thus stepped armature 216 around to the thirtieth contact of the founth combination switch, which is the fourth contact 214 and armature 190 around to the thirtieth contact of the first combination switch, which is the fourth contact 188.

The fifteenth pulse will move the pawl of armature 172 into engagement with the next tooth on ratchet 173, and will again open contact 166. However, since the circuit to relay 64 is already open, this movement of contact 166 will not affect that relay or contact 114; and hence no further impulse is transmitted to indicator 116. The passing of the fifteenth pulse will have no affect upon the relay 156 since the circuit to that relay is already open, but it will advance armature 216 into engagement with the thirty-first contact of the fourth combination switch, which is the fifth contact 214; and thus the buzzer action of contact 164 and relay 162 will promptly step the armature 216 around to the fortieth contact of the fourth combination switch, which is the fourteenth contact 214.

The sixteenth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth on ratchet 173, and will again open contact 166. However since the circuit to relay 64 is still open, this movement of contact 166 will not affect that relay or contact 114; and hence no further impulse is transmitted to indicator 116. The passing of the sixteenth pulse will have no eliect upon the relay 156 since the circuit to that relay is still open, but it will advance armature 216 into engagement with the forty-first contact of the fourth combination switch, which is the fifteenth contact 214; and then the buzzer action of contact 164 and relay 162 will promptly step the armature 216 around to the fiftieth contact of the fourth combination switch, which is the twenty-fourth contact 214. The seventeenth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth of ratchet 173, and will again open contact 166. Since the circuit to relay 64 is still open, this movement of contact 166 will not cause an impulse to be transmitted to indicator 116. The passing of the seventeenth pulse will have no effect upon relay 156 since the circuit to that relay is still open, but it will advance armature 216 into engagement with the fiftyfirst contact of the fourth combination switch, which is the twenty-fifth contact 214. No buzzer action will ensue because the twenty-fifth contact 214 is not connected to conductor288. At the same time the spring advanced armature 216 into engagement with the twentyfifth contact 214, that spring advanced armature 206 into engagement with the fifty-first contact of the third combination switch, which is the twenty-fifth contact 204; thus completing a circuit from .the source of negative power adjacent junction 60, through junction 60, through contact 54, through relay 292, through junction 306 through twenty-fifth contact 204, through armature 206, through junctions 262 and 62 and 58, through contacts 52 and 82, through junctions 88 and 90, and through junctions 153 and 152 to the source of positive power adjacent junction 152. The resulting flow of current through relay 292 will move me ns 17 armature 294 into engagement with terminal 295, will move armature 296 into engagement With terminal 297 and will move armature 293 out of engagement with terminal 300 and into engagement with terminal 302. A holding circuit for relay 292 is established when relay 292 is energized, and that circuit will extend from the source of negative power adjacent junction 60, through junction 60, through contact 54, through relay 292, through junctions 306 and 308, through armature 294, through terminal 295, through junctions 304 and 260, through junctions 258 and 256 and 254, and through junctions 154 and 152 to the source of positive power adjacent junction 152. This holding circuit will keep relay 292 energized, and thus separate the pre-code signal commutator switches from relay 156 and from contact 166 of relay 162, until relay 48 is de-energized. A round-counting circuit is es tablished when the relay 292 is energized, and that circuit will extend from the source of negative power adjacent electromagnet 38, through armature 296, through terminal 297, through conductor 286, through either the firs-t or second contact 200 of the third combination switch, through armature 202, through junctions 262 and 62 and 58, through contacts 52 and 82, through junctions 88 and 90 and through junctions 153 and 152 to the source of positive power adjacent junction 152. This round-counting circuit is open, and it will remain open until armature 202 is advanced into engagement with the first contact 202; but thereupon that circuit will be completed and will energize electromagnet 38, thus advancing ratchet 32 and armature 24 the distance of one contact. When relay 292 was energized, the group of five commutator switches was connected to relay 156 and the con-tact 166 of relay 162 through terminal 302 and armature 298; and for the remainder of the cycle of the signal generator, the five commutator switches and the second combination switch will act through contact 166 to control relays 64 and 112.

The eighteenth pulse will move the pawl of armature 172 into engagement with the next tooth of ratchet 173, and will again open contact 166. Since the circuit to relay 64 is still open, this movement of contact .166 will not cause an impulse to be transmitted to indicator 116. The passing of the eighteenth pulse will have no effect pon relay 156 since the circuit to that relay is still open, but it will advance armature 216 into engagement with the fiftysecond contact of the fourth combination switch, which is the twenty-sixth contact 214, and it will advance armature 206 into engagement with the fifty-second contact of the third combination switch, which is the twenty-sixth contact 204. No buzzer action will occur because the twenty-sixth contact 214 is not connected to conductor 288. The movement of armature 206 out of engagement with the twenty-fifth contact 204 will not tie-energize relay 292 because of the previously established holding cir' cuit for that relay.

The nineteenth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth of ratchet 173 and will open the contact 166; but no impulse will be sent to indicator 116 because "the circuit to relay 64 is still open. 'The passing of the nineteenth pulse will advance armature 186 into engagement with the first contact 184, 'will advance armature 194 into engagement with the first contact 192, will advance the armature 202 into engagement with the first contact 200, and will advance the armature 212 into engagement with the first contact 210. The 'engagement be'tween armature 186 and the first contact 184 will have no eifect upon the operation of the signal generator because the circuit to relay 156 and contact 166 of relay 162 is open at terminal 300 and armature 2'98. The engagement of armature 212 with the first contact 210 will have no e'flfect upon the operation of the signal generator because that contact is not connected to any other part of the signal generator. The engagement between armature 202 and the first contact 200 will energize the round-counting circuit previously described and will advance the armature 24 into engagement with the first contact 26. The engagement between armature 194 and the first contact 192 will permit current to flow from the source of negative power adjacent relay 156 through relay 156 to the junction 160, and it will also permit current to flow from the source of negative power adjacent relay 64, through relay 64, through junction and through contact 166 to junction and then the combined current will flow through junction 160, through armature 298, through terminal 302, through junctions 278 and 275, and then in parallel through jumper 276 and commutator 236 to the first contact 234, through the first contact 192, through armature 194, through junctions 258 and 256 and 254, and through junctions 154 and 152 to the source of positive power adjacent junction 152. This will open contact 158 and prevent buzzer action when armature 212 engages the second contact 210; and it will energize relay 64, thus opening contact 66 and de-energizing relay 112 to permit contact 114 to close.

The twentieth pulse from the relay chain will move the pawl of armature 172 into engagement with the next tooth of ratchet 173 and will open contact 166. This movement of contact 166 will de-energize relay 64 and will cause relay 112 to open contact 114, thus sending an impulse to indicator 116. The complete absence of impulses to indicator 116 during the generation of the fourteenth'through the nineteenth pulses from the relay chain provides .a ,sizable blow to separate the pre-code signal from the code signal. ,The passing of the twentieth pulse will permit contact 166 to close and will permit the spring 176 to advance armature 202 into engagement with the second contact 200, to advance armature 212 into engagement with the second contact 210, and to advance the armature 194 into engagement with the second contact 192. "The en.- gagement between armature 202 and the second contact 200 does not change the operation of the signal generator but merely assures an energization of electromagnet '38 that is long enough to advance the armature 24 into engagement with the first contact 26. The engagement between armature 212 and the second contact 210 will not affect the operation of the signal generator because .contact 158 is held open by relay 156. The engagement between .armature 194 and the second contact 192 will act through the closed contact 166 to energize relay 64 and thus close contact 114 by de-energizing relay 112.

The generation of the twenty-first through the twentyfourth pulses, and the passing of the twenty-first through the twenty-third pulses, will successively open contact 166 and thus cause four additional impulses to be sent to indicator 116., and will successively step armature 194 into engagement with the third through the fifth contacts 192. As the twenty-fourth pulse' passes, the spring 176 will move armature 194 outof engagement 'with the fi'fth con tact 1'92 and into engagement with the sixth contact 192 and this will immediately break the circuit to relay 64 since the .commutator 236 does not engage the sixth contact '234 that corresponds to the contact 192 engaged by armature 194. As a result, relay 64 will remain .de-energ'ized and relay 112 will hold contact 114 open. The twenty-fifth pulse will not affectrelay 64 even though it opens contact 166, since the circuit to relay 64 is still open. As the twenty-fifth pulse passes, the slow-acting relay 156 will release .its contact 158 because the circuit to that relay was broken when the armature 194 moved out of engagement with the fifth contact 192 and that break in the circuit kept that relay from receiving the twenty-fifth ,pulse which it needed to continue to remain energized. Before the twenty-sixth pulse can be generated, the buzzer action of contact 164 and relay 162 will have stepped armature .194 around to the tenth contact 192. The twenty-sixth pulse will open contact .166 but such action will not aflect relay -64 since .the circuit to that relay is still open. During the .twenty-tfifth and twentysixth :pulses from the relay chain, :no impulses were transmitted to the indicator 1 16; ;and the resulting absence of impulses constitutes a iblow that differentiates the :first 19 numeral of the code signal from the other numbers of that signal.

As the twenty-sixth pulse passes, the spring 176 will advance armature 194 into engagement with the eleventh contact 192, and will permit contact 166 to close. Immediately, current will flow from the source of positive power adjacent junction 152, through junctions 152 and 154, through junctions 254 and 256 and 258, through armature 194, through the eleventh contact 192, through the first contact 238, through the commutator 240, through the junctions 280 and 278, terminal 302, through armature 298 to junction 160; and part of that current will energize relay 156 and the rest will flow through contact 166 and through junction 110 to relay 64. The energization of relay 156 will open contact 158 and halt further buzzer action, and the energization of relay 64 will de-energize relay 112 and permit contact 114 to close.

The generation of the twenty-seventh through the thirty-second pulses, and the passing of the twenty-seventh through the thirty-first pulses, will successively open contact 166 and thus cause six impulses to be sent to indicator 116, and will successively step armature 194 into engagement with the twelfth through the sixteenth contacts 192. As the thirty-second pulse passes the spring 176 will move armature 194 into engagement with the seventeenth contact 192; and this will immediately break the circuit to relay 64 since the commutator 240 does not engage the seventh contact 238 which corresponds to the contact 192 engaged by armature 194. As a result, relay 64 will remain de-energized and relay 112 will hold contact 114 open. The thirty-third pulse will not aifect relay 64 even though it opens contact 166, since the circuit to relay 64 is still open. As the thirty-third pulse passes, the relay 156 will release its contact 158; and before the thirtyfourth pulse can be generated, the buzzer action of contact 164 and relay 162 will have stepped armature 194 around to the twentieth contact 192. The thirty-fourth pulse will open contact 166 but such action will not atfect relay 64 since the circuit to that relay is still open. During the thirty-third and thirty-fourth pulses, no impulses were sent to indicator 116; and thus a blow was provided.

As the thirty-fourth pulse passes, the spring 176 will advance armature 194 into engagement with the twentyfirst contact 192, and will permit contact 166 to close. Immediately, current will flow through the twenty-first contact 192, through the first contact 242 and through commutator 244 to relays 156 and 64; thus halting further buzzer action and permitting contact 114 of relay 112 to close. The generation of the thirty-fifth through the forty-first pulses, and the passing of the thirty-fifth through the fortieth pulses, will successively open the contact 166 and thus cause seven impulses to be sent to indicator 116, and will successively step armature 194 into engagement with the twenty-second through the twenty-sixth contact 192 and Will step armature 198 into engagement with the first contact 196. As the forty-first pulse passes, the spring 176 will move armature 198 into engagement with the second contact 196; and this will immediately break the circuit to relay 64 since the commutator 244 does not engage the eighth contact 242 that corresponds to the contact 196 engaged by the armature 198. As a result, relay 64 will remain de-energized and relay 112 will hold relay 114 open.

The forty-second pulse from the relay chain will not affect relay 64 even though it opens contact 166, because the circuit of relay 64 is still open. As the forty-second pulse passes, the relay 156 will release its contact 158; and before the forty-third pulse can be generated, the buzzer action of contact 164 and relay 162 will have stepped armature 198 around to the thirtieth contact of the second combination switch, which is the fourth contact 196. The forty-third pulse will open contact 166 but such action will not affect relay 64 since the circuit to that relay is still open. During the forty-second and the forty-third pulses, no impulses were sent to indicator 116; and thus a blow was provided.

As the forty-third pulse passes, the spring 176 will advance armature 198 into engagement with the thirtyfirst contact of the second combination switch, which is the fifth contact 196, and will permit contact 166 to close. Immediately, current will flow through the fifth contact 196, through the first contact 246 and through commutator 248 to relays 156 and 64; thus halting further buzzer action and permitting contact 114 of relay 112 to close. Immediately, current will flow through the fifth fifty-first pulses, and the passing of the forty-fourth through the fiftieth pulses, will successively open the contact 166 and cause eight impulses to be sent to indicator 119, and will successively step armature 198 into engagement with the sixth through the twelfth contacts 196. As the fifty-first pulse passes, the spring 176 will move armature 198 into engagement with the thirteenth contact 196; and this will immediately break the circuit to relay 64 since the commutator 248 does not engage the ninth contact 246 that corresponds to the contact 196 engaged by the armature 198. As a result, relay 64 will remain de-energized and relay 112 will hold relay 114 open.

The fifty-second pulse from the relay chain will not affect relay 64 even though it opens contact 166, because the circuit of relay 64 is still open. As the fifty-second pulse passes, the relay 156 will release its contact 158; and before the fifty-third pulse can be generated, the buzzer action of contact 164 and relay 162 will have stepped armature 198 around to the fortieth contact of the second combination switch, which is the fourteenth contact 196. The fifty-third pulse will open contact 166 but such action will not affect relay 64 since the circuit to that relay is still open. During the fifty-second and fifty-third pulses, no impulses were sent to indicator 1.16; and thus a blow was provided.

As the fifty-third pulse passes, the spring 176 will advance armature 198 into engagement with the fifteenth contact 192 and will permit contact 166 to close. Immediately, current will flow through the fifteenth contact 196, through the first contact 250 and through commutator 252 to relays 156 and 64; thus halting further buzzer action and permitting contact 114 of relay 112 to close. The generation of the fifty-fourth through the sixty-second pulses, and the passing of the fifty-fourth through the sixty-first pulses, will successively open the contact 166 and thus cause nine impulses to be sent to indicator 116, and will successively step armature 198 into engagement with the sixteenth through the twenty-third contacts 196. As the sixty-second impulse passes, the spring 176 will move armature 198 into engagement with the twenty-fourth contact 196, which is the fiftieth contact of the second combination switch. This will immediately break the circuit to relay 64 since that fiftieth contact of the second combination switch is not connected to any other part of the signal generator. As a result, relay 64 will remain de-energized and relay 112 will hold relay 114 open.

The sixty-third pulse from the relay chain will not affect relay 64 even though it opens contact 166, because the circuit of that relay is still open. As the sixty-third pulse passes, the relay 156 will release its contact 158, and armature 216 will engage the twenty-fifth contact 214; but no buzzer action will occur because that twentyfifth contact is not connected to conductor 238. The armature 206 will engage the twenty-fifth contact 204 at the same time armature 216 engages the twenty-fifth contact 214; and this engagement will complete a circuit from the source of negative power adjacent junction 60 through relay 292 to the source of positive power adjacent junction 152. The completion of this circuit will not, however, affect the operation of the signal generator since the relay 292 is held in an energized state by the holding circuit through armature 294 and terminal 295.

The sixty-fourth pulse from the relay chain will not affect relay 64 even though it opens contact 166, because the circuit to relay 64 is still open. As the sixty-fourth pulse passes, armature 198 will engage the twenty-sixth contact 196 and armature 206 will engage the twentysixth contact 204; but neither engagement affects the operation of the signal generator. The sixty-fifth pulse will not affect relay 64 since the circuit to that relay is still open; but as that pulse passes, the armature 194 will re-engage the first contact 192 and the armature 202 will re-engage the first contact 200. The re-engagement of armature 202 with the first contact 200 closes the roundcounting circuit and energizes electromagnet 38, thus causing ratchet 32 to advance armature 24 into engagement with the second contact 26. For the moment, this latter engagement does not affect the operation of the signal generator because the armature 16 does not engage the corresponding contact 20. The re-engagement of armature 194 with the first contact 192 simultaneously energizes relay 156 and relay 64 through the first contact 234 and the commutator 236. Succeeding pulses from the relay chain will step the shaft 182 through further rounds or cycles, and will transmit to indicator 116 the numerals and blows prescribed by the settings of commutators 236, 240, 244, 248 and 252. At the conclusion of the fifth round, the round-counting circuit will move armature 24 into engagement with the lowermost contact 28; and this will complete a circuit that starts at the source of negative power adjacent relay 78 and extends through relay 78, through armature 24, through the contacts 28 and 22, through armature16 and through terminal .10 to the source of positive power adjacent terminal 10. This circuit will energize relay 78, thus opening contacts 80 and 82 and closing contact 84. The opening of contact 80 will break the holding circuit of relay 48; and all of the four contacts of that relay will open. The opening of contact 82 will break the circuit to the relay chain, will break the pulsing circuit to relay 162, and will break the round-counting circuit. The breaking of the pulsing circuit to relay 162 will break the circuit to relay 64. The opening of contact 54 of relay 48 breaks the circuit of relay 292. The closing of contact 84 establishes a circuit that extends from the source of negative electricity adjacent electromagnet 42, through electro-magnet 42, through contact 84 and through junctions 90 and 153 and 152 to the source of positive power adjacent junction 152. This circuit moves the lever 40 and disengages the pawl of lever 36 and the detent 34 from the ratchet 32, whereupon that ratchet and the armature 24 rotate to the position shown in the drawing. Such rotation completes the cycle of operation of the signal generator by breaking the circuit through relay 78; thus readying the signal generator for another manuallyinitiated cycle.

During the foregoing cycle, the signal generator generated and sent a number of spaced impulses to the indicator 116 and then generated and sent four sets of spaced numerals to that indicator. The first group of numerals constituted a pre-code signal, while the second group of numerals constituted the code signal, and that code signal was repeated four times. During the foregoing cycle the signal generator unhurriedly generated the impulses which made up the numerals and then quickly stepped the armatures to the beginning of the next numeral. With such a signal generator, the waste time involved in gen, erating and sending a pre-code signal and a code signal composed of small numerals is very little, if any, greater than the waste time involved in sending a pre-code signal and a code signal composed of large numerals. In this way, the present signal generator minimizes the busy time of the circuit.

The settings of the commutators 220, 228, 232, 236, 240, 244,, 248, and 252 can be changed merely by grasping the commutators and rotating them. Thus, while the signal generator may be pre-set to deliver a desired combination of pre-code signal and code signal, that signal generator can be changed to generate and send any desired pre-code signal and code signal. In fact, the settings of the commutators could be changed during a fire by authorized personnel. Similarly, the number of rounds which are desired can be changed by authorized personnel, either before or during a fire. If it is desired to send only a pre-code signal, the armature 16 will be set on the first contact 20. If it is desired to send one pre-code signal and one code signal, that armature 16 will be set on the second contact 20. Engagement of the armature 16 with other of the contacts 20 will provide the desired number of repeats of the code signal.

It may some times happen that authorized personnel may wish to cancel the signal being sent by the signal generator. This can be due to changes in the conditions at the fire after the initial cycle is started, or can be due to a desire to correct errors made by that authorized personnel in making a change in the code signal. In any event, it is only necessary for the authorized personnel to press the push button 14 against the terminals 10 and 12. This establishes a circuit from the source of negative power adjacent the relay 92, through the relay 92, through the terminal 12, through the push button 14, and through the terminal 10 to the source of positive power adjacent terminal 10. This will energize the relay 92 and will move all of the four contacts 94, 96, 98 and 100 to closed position. Closing of the contact 94 will establish a circuit from the source of negative power adjacent the relay 78, through the relay 78, through the contact 94, through junctions 102 and 153 and 152 to the source of positive power adjacent the junction 152. This will energize the relay 78, which will open the circuits to the various component parts of the signal generator, as outlined above. Closing of the contacts 6 and 98 will establish a circuit from the source of negative power adjacent relay 162, through the relay 162, through the junction 168, through the contact 164, and through the junction 264 either to the armature 212 or the armature 216 and thence either through the conductor 288 and junction 104 and contact 96 to the junction 108, or through the conductor 290 direct to the junction 108, and thence through the contact 98 and the junctions 106 and 102 and 153 and 152 to the source of positive power adjacent the junction 152. This circuit will initiate a buzzer action by contact 164 and relay 162 which will step the shaft 182 around to the end of its cycle; that cycle being concluded when the armature 212 engages the first contact 210 which is not connected to any other part or" the circuit The closing of the contact 1110 establishes a circuit from the source of negative power adjacent the relay 64, through the relay 64, through the junction 110, through the-contact 100, through the junctions 1% and 102 and 153 and 152 to the source of positive power adjacent the junction 152. This latter circuit energizes the relay 64 and opens the contact 66, thus permitting the relay 112 to release the contact 114. This readies the signal generator for another manually-initiated cycle, and upon the release of the push button 14, a new cycle can be initiated by pushing the switch 44. Prior to the closing of the switch 44, the setting of the armature 16 or the settings of any of the commutators of the commutator switches can be changed as desired.

The signalling key 74 can be closed at any time by authorized personnel. The closure of that key will complete a circuit from the source of negative power adjacent the relay 112, through the relay 112, through the junction 72 and through the key 74 to the source of positive power adjacent that key. Closure of the key 74 will open the contact 114 and send an impulse to the indicator 116. The key 74 can be used for manual signalling or can be used for testing of the equipment.

If it is desired to use this signal generator in areas where a pre-code signal is not needed, or is not desired, the commutators 220, 228, and 232 can be left in the positions shown in the drawing. In such a case, the cam 222' which is connected to the commutator 220 will hold the switch 224 closed. This switch establishes a circuit which begins at the source of negative power adjacent the junction 60, and extends through junction 60, through contact 54, through relay 292, through junctions 306 and 308, through switch 224, through junction 364, through junctions 260 and 258 and 256, through junctions 25 i and 154 and 152 to the source of positive power adjacent junction. 152. This energizes the relay 292 and immediately pre-sets the code signalling circuit and establishes the holding circuit for the relay 292. Where this is done, the signal generator will begin to count its rounds immediately rather than have a pre-code signalling round.

The jumpers 2'70 and 276 are used to establish a complete circuit for relay 156 whenever the start switch 44 is closed to initiate a signal cycle, irrespective of the settings of the commutators 220 and 236. Such an arrangement is desirable since it avoids a premature buzzer action that could distort the pro-code signal or code signal to be generated. Once the armatures 186 and 1% have moved out of engagement with the first contacts 184 and 1% respectively, the jumpers 270 and 276 will have no effect; and the settings of the commutators 220, 223, 232, 236, 240, 244, 248 and 252 will determine when and how long the shaft 182 will advance by pulse action or buzzer action.

The switches 142 and 143 are shown as being manually-operated single pole, double throw switches, but they could be made to operate electro-magnetically. Those switches could have a coil that would move the armatures of those switches to their lower positions and could have a spring that would bias those armatures to 0 their upper positions. Where this was done, the relays 124, 1.30 and 134 would provide the pulses for the first round or rounds, and thereafter the relays 124, 130, 134 and 138 would provide the pulses for the remaining rounds. The coil for the switches would be energized when a contact, not shown, on the ratchet 32 would strike another contact and close the circuit to that coil. The setting of that contact would determine the number of rounds to be pulsed at the faster and slower rates; and the contact and coil would automatically shift from the faster pulse rate to the slower pulse rate.

The coil 162 is a part of the advancing mechanism for the shaft 182 as well as being a part of a two contact relay. If desired, of course, the advancing mechanism could be provided with a coil that was separate and distinct from a coil that operated the contacts 164 and 166; provided both coils were connected in parallel.

The signal generator provided by the present invention is extremely versatile, it can accommodate a huge range of pre-code signals and code signals, and it can be reset quickly and easily. Moreover, this signal generator minimizes the busy time of the circuit.

Whereas a preferred embodiment of the present invention has been shown and described in the drawing and accompanying description, it should be apparent that various changes can be made in the form of the invention without affecting the scope thereof.

What I claim is:

l. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electro-responsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pro-determined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pro-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, nine contacts in the spaced groups of contacts on said multi-contact switch, nine contacts on each of said selector switches, a jumper that completes the circuit to the first contact of one of said selector switches irrespective of the setting of said selector switch, a source of short and fast impulses for said advancing mechanism, a second multi-contact switch, the contacts of said sec- 0nd multi-contact switch being grouped in groups of nine that are spaced apart by spacer contacts, a bridging conductor that interconnects the contacts in said spaced groups of contacts, a second bridging conductor that interconnects said spacer contacts, a connector extending between the armatures of said multi-contact switches to connect said armatures for conjoint movement, the armaturcs of said multi-contact switches simultaneously engaging corresponding contacts of said multi-contact switches, a third contact that normally disconnects the first said bridging conductor from said source of short and fast impulses, a third electro-responsive element that normally holds said third contact in disconnecting position, a fourth contact that can be closed to connect the list said bridging conductor to said source of short and fast impulses and a fifth contact that can be closed to connect said second bridging conductor to said source of short and fast impulses, said third elcctro-responsive element holding said third contact in disconnecting position whenever said signal generator is operating and the armature of the first said multi-contact switch engages any of the contacts of the first said multi-contact switch that are conneced to said pro-determined groups of contacts on said selector switches, said fourth and fifth contacts being closable to rapidly impulse the armatures of said multi-contact switches to the ends of their cycles irrespective of the momentary positions of said armatures.

2. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electro-responsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pro-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a source of short and fast impulses for said advancing mechanism, a second multi-contact switch, the contacts on said second multi-contact switch being arranged in spaced groups, spacer contacts between said spaced groups of contacts, a bridging conductor that interconnects the contacts of said spaced groups of contacts, a second bridging conductor interconnecting said spacer contacts, a connector extending between the armatures of said multi-contact switches to connect said arrnatures for conjoint movement, the spaced groups of contacts on the first said multi-contact switch having the same number of contacts as the spaced groups of contacts on said second multi-contact switch and the armatures of said multi-contact switches simultaneously engaging corresponding contacts of said spaced groups of contacts, and a clearing switch that selectively connects said bridging circuits to said source of short and fast im- 25 pulses, a third contact that selectively connects the first said bridging conductor to said source of short and fast impulses, and a third electro-responsive element that holds said third contact in disconnecting position whenever said signal generator is operating and the armature of the first said multi-contact switch engages any of the contacts of the first said multi-contact switch that are connected to said pre-determined groups of contacts on said selector switches but that releases said third contact whenever said armature of the first said multi-contact switch remains out of engagement with those contacts of the first said multi-contact switch that are connected to the said predetermined groups of contacts on said selector switches.

3. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a mul'ti-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and reestablish the said first and second circuits, a source of short and fast impulses for said advancing mechanism, a source of pulses for said advancing mechanism, a second multi-contact switch, the contacts of said second multi-contact switch being disposed in spaced groups, spacer contacts on said second multicontact switch between said groups of contacts, a bridging conductor that interconnects the contacts of said spaced groups, a second bridging contact that interconnects said spacer contacts, a connector extending between the armatures of said multi-contact switches to connect said armatures for conjoint movement, the contacts of the spaced groups of contacts on said multi-contact switches being comparable and being simultaneously engaged by the armatures of said multi-contact switches, a slow-acting relay that normally disconnects the first said bridging conductor from said source of short and fast impulses but that connects the first said conductor to said source of pulses whenever the armature of the first said multicontact relay remains out of engagement with those contacts of the first said multi-contact switch that are connected to said pro-determined groups of contacts on said selector switches, a second relay that is selectively energizable to connect said bridging conductors to said source of short and fast impulses, said source of pulses normally being connected to said advancing mechanism but being disconnected therefrom by said second relay.

4. A signal generator for alarm circuits which cm prises a contact zconnectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said .multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi contact switch and through "a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said predetermined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a source of short and fast impulses for said advancing mechanism, a second multi-contact switch, the contacts on said second multi-conta'ct switch being arranged in spaced groups, spacer contacts between said spaced groups of contacts, a bridging conductor that interconnects the contacts of said spaced groups of contacts, a second bridging conductor interconnecting said spacer contacts, a connector extending between the armatures of said multi-contact switches to connect said armatures for conjoint movement, the spaced groups of contacts on the first said multi-contact switch having the same number of contacts as the spaced groups of contacts on said second multi-contact switch and the armatures of said multi-contact switches simultaneously engaging corresponding contacts of said spaced groups of contacts, and a clearing switch that selectively connects said bridging circuits to said source of short and fast impulses.

5. A signal generator for alarm circuits which comprises a contact :connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of manually pre-settable selector switches, conductors that exten-d between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said lelectro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches e'ing adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a shaft to carry said armature of said multi-contact switch, said advancing mechanism including a ratchet that rotates with said shaft and an armature that drives said ratchet and a spring that drives said armature, said second electroresponsive element being a part of said advancing mechanism and being energizable to distort said spring and to move said armature into engagement with the next tooth of said ratchet.

6. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-conta'ct switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of manually pre-settable selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, .a first circuit that extends through one group of contacts on said multi-contact switch and through a predetermined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a source of 27 pulses for said second electro-responsive element, said second electro-responsive element being a part of said advancing mechanism whereby pulses from said source will interrupt said first and second circuits and will advance the armature of said multi-contact switch.

7. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multicontact switch and through a pro-determined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and reestablish the said first and second circuits, a source of pulses to actuate said advancing mechanism and a source of short and fast impulses to actuate said advancing mechanism, and a third electro-responsive element that normally holds said source of short and fast impulses inactive whenever said armature of said multi-contact switch engages any of the contacts of said multi-contact switch that are connected to said pre-determined groups of contacts on said selector switches but that releases said source of short and fast impulses whenever said armature of said multi-contact switch is moved out of engagement with those contacts of said multi-contact switch that are connected to said predetermined groups of contacts on said selector switches, said second electro-responsive element being connected to said source of pulses whenever said signal generator is operating, said third electro-responsive element being connected to said source of pulses whenever said signal generator is operating and said armature of said multi-contact switch engages any of the contacts of said multi-contact switch that are connected to said pre-determined groups of contacts on said selector switches.

8. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said eleetro-responsive element, said selector switches being adjustable to select said predetermined groups of contacts, a second contact that is common to said first and second circuits, a second cl-ectro-responsive element that can move said second contact and thus interrupt and i e-establish the said first and second circuits, at source of pulses to actuate said advancing mechanism and a source of short and fast impulses to actuate said advancing mechanism, and a third clcctro-responsive element that normally holds said source ot short and fast impulses inactive whenever said armature of said multi-contact switch engages any of the contacts of said multi-contact switch that are connected to said pre-determined groups of contacts on said selector switches but that releases said source of short and fast impulses whenever said armature of said multicontact switch is moved out of engagement with those contacts of said multi-contact switch that are connected to said pro-determined groups of contacts on said selector switches, said selector switches being commutator switches, each of said selector switches having nine contacts, the commutator of any of said selector switches being selectively adjustable to interconnect from one to nine of the contacts of that selector switch, said third electro-responsive element being a slow-acting relay' 9. A signal generator for alarm circuits which cornprises a contact connectible in an alarm circuit, an electro responsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pro-determined groups of contacts on one of said selector switches to said electro-responsive element, a second circuit tint extends through another group of contacts on said multicontact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of con tacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and rte-establish the said first and second circuits, a source of pulses to actuate said advancing mechanism and a source of short and fast impulses to actuate said advancing mechanism, and a third electro-responsive element that normally holds said source of short and fast impulses inactive whenever said armature of said multicontact switch engages any of the contacts of said multicontact switch that are connected to said pre-determined groups of contacts on said selector switches but that releases said source of short and fast impulses whenever said armature of said multi-contact switch is moved out of engagement with those contacts of said multi-contact switch that are connected to said pre-determined groups of contacts on said selector switches, said selector switches having nine contacts, each of said selector switches being adjustable to interconnect from one to nine of the contacts thereof, said spaced groups of contacts on said multi-contact switch containing nine contacts.

10. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a predetermined group of contacts on one of said selector switches to said electro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a pre-determined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pro-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, at source of pulses to actuate said advancing mechanism and a source of short and fast impulses to actuate said advancing mechanism,

and a third electro-resp'onsive element that normally holds said source of short and fast impulses inactive whenever said armature of said multi-contact switch engages any of the contacts of said multi-contact switch that are con nected to said pre-determined groups of contacts on said selector switches but that releases said source of short and fast impulses whenever said armature of said multicontact switch is moved out of engagement with those contacts of said multi-contact switch that are connected to said predetermined groups of contacts on said selector switches.

11. A signal generator for alarm circuits which cornprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of manually pre-settable selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multicontact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can movesaid second contact and thus interrupt and re-establish the said first and second circuits, a source of pulses for said advancing mechanism and said second electro-responsive element, said source of pulses including a chain of four relays and a switch that selectively separates one of the said four relays from said relay chain to provide a difierent pulse frequency.

12. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electro-responsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of manually pre-settable selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multicontact switch, a first circuit that extend-s through one group of contacts on said multi-contact switch and through a pre-determined group of contacts on one of said selector switches to said electro-responsive element, a secnd circuit that extends through another group of'contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a source of pulses for said advancing mechanism, said source of pulses having a switch that is movable to one position to energize said source for the generation of pulses at one frequency and that is movable to another position to energize said source for the generation of pulses at a different frequency.

13. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electro-responsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a group of manually pre-settable selector switches that can be set to define a precode signal, a second group of manually pre-settable selector switches that can be set to define a code signal, a shaft that can rotate through a cycle, an advancing mechanism for said shaft, a pair of spaced terminals, 21 second contact that can be selectively moved into engagement with one or the other of said spaced terminals but cannot simultaneously engage both of said terminals, a second electro-responsive element that can cause movement of said second contact into and out of engagement with either of said spaced terminals, a first circuit extending from the first group of selector switches I to the said one terminal, a second circuit extending from the second group of selector switches to said other terminal, a switch responsive to cycling of said shaft to control the energization of said second electro-responsive element, said second contact normally engaging said one terminal but responding to actuation of said second electroresponsive element to engage said other terminal.

14. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a group of selector switches that can be set to define a precode signal, a second group of selector switches that can be set to define a code signal, a shaft that can rotate through a cycle, an advancing mechanism for said shaft,

a pair of spaced terminals, a second contact that can be selectively moved into engagement with one or the other of said spaced terminals but cannot simultaneously engage both of said terminals, a second electro-responsive element that can cause movement of said second contact into and out of engagement with either of said spaced terminals, a first circuit extending from the first group of selector switches to the said one terminal, a second circuit extending from the second group of selector switches to said other terminal, a switch responsive to cycling of said shaft to control the energization of said second electroresponsive element, said second contact normally engaging said one terminal but responding to actuation of said second electro-responsive element to engage said other terminal, and a second switch that can control the energization of said second electro-responsive element, said second switch being interconnected with one of the selector switches of said first group of selector switches so said second switch causes said second electro-responsive element to place said second contact in engagement with said other terminal whenever said one selector switch is in a neutral position.

15. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a group of manually pre-settable selector switches that can be set to define a precode signal, a second group of manually pre-settable selector switches that can be set to define a code signal, a shaft that can rotate through a cycle, an advancing mechanism for said shaft, a pair of spaced terminals, a second contact that can be selectively moved into engagement with one or the other of said spaced terminals but cannot simultaneously engage both of said terminals, a second electro-responsive element that can cause movement of said second contact into and out of engagement with either of said spaced terminals, a first circuit extending from the first group of selector switches to the said one terminal, a second circuit extending from the second group of selector switches to said other terminal, a round-counting circuit that responds to rotation of said shaft to cause said second electro-responsive element to move said second contact out of engagement with said one terminal and into engagement with said other terminal.

16. A signal generator for alarm circuits which comand serially spaced groups of contacts on said multi-contact switch, a first circuit that extends through one group of contacts on said multi-contact switch and through a pro-determined group of contacts on one of said selector switches to said electro-responsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element, said selector switches being adjustable to select said pre-determined groups of contacts, a second contact that is common to said first and second circuits, a second electro-responsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a relay that can interrupt said circuits when it is energized, and a clearing switch that selectively energizes said relay.

17. A signal generator for alarm circuits which comprises a contact connectible in an alarm circuit, an electroresponsive element that can cause movement of said contact and thus interrupt and re-establish said alarm circuit, a multi-contact switch, an advancing mechanism for the armature of said multi-contact switch, a plurality of selector switches, conductors that extend between the contacts of said selector switches and serially spaced groups of contacts on said multicontact switch, a first circuit that extends through one group of contacts on said multicontact switch and through a pre-determined group of contacts on one of said selector switches to said electroresponsive element, a second circuit that extends through another group of contacts on said multi-contact switch and through a predetermined group of contacts on another of said selector switches to said electro-responsive element,

said selector switches being adjustable to select said predetermined groups of contacts, a second contact that is common to said first and second circuits, a second electroresponsive element that can move said second contact and thus interrupt and re-establish the said first and second circuits, a second switch with a manually adjustable armature, a third multi-contact switch, a third electroresponsive element to advance the armature of said third multi-contact switch, conductors that extend between corresponding contacts on said second and third multicontact switches, a clearing circuit extending to the armature of said second multi-contact switch and extending from the armature of said third multi-contact switch, and a switch that closes at the end of each cycle of said advancing mechanism and energizes said third electro-responsivc element, said third electro-responsive element stepping the armature of said third multi-contact switch into engagement with successive contacts on said third multi-contact switch, said clearing circuit being energized when the armature of said third multi-contact switch engages a contact corresponding to the contact of the second multi-contact switch that is engaged by the armature of that second multi-contact switch.

References Cited in the file of this patent UNITED STATES PATENTS 814,386 Marean Mar. 6, 1906 1,714,302 Fisher et al May 21, 1929 1,846,218 Lomax Feb. 23, 1932 1,957,672 Saunders May 8, 1934 2,116,372 Weld May 3, 1938 

